A synchronous control method for ultrasonic generator double-machine linkage welding
By employing a master-slave ultrasonic generator collaborative control method, hardware consistency and software differentiation between the two ultrasonic generators are achieved. This solves the cost and complexity issues of collaborative control in high-power ultrasonic welding, improves system reliability and application scope, and reduces inventory management difficulty.
Patent Information
- Application Number
- CN202511321371.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-16
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2045-09-16
AI Technical Summary
In existing high-power ultrasonic welding technology, the collaborative control method of two ultrasonic generators has problems such as high R&D costs, limited application scope, high system complexity, difficulty in independently monitoring and protecting transducers, and complex inventory management.
It adopts a master-slave ultrasonic generator structure, and realizes signal transmission through a synchronous expansion board and communication cable. The master ultrasonic generator generates master and slave drive signals. The two ultrasonic generators are identical in hardware and are only distinguished by software. The master and slave are controlled in a coordinated manner, supporting 0° to 360° phase adjustment, independent monitoring and protection.
It reduces R&D and production costs, expands the application scope, simplifies the system structure, improves system reliability and monitoring capabilities, reduces inventory management complexity, simplifies wiring, and ensures reliable signal transmission.
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Figure CN120901455B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of ultrasonic welding equipment, in particular to the improvement of the method for the coordinated control of two ultrasonic generators during high-power ultrasonic welding. BACKGROUND
[0002] In the application of high-power ultrasonic welding, especially in the case of welding difficult materials or needing to shorten the welding cycle, it is usually necessary to use two transducers for push-pull driving to provide more vibration energy. The ultrasonic generator driving two transducers requires that the two driving signals have the same frequency and a phase difference of 180°.
[0003] In the prior art, a single power supply is usually used in combination with a balun transformer (balanced transformer) to achieve double-transducer driving. This scheme uses two identical transformer secondary coils, but the same name ends are opposite, thereby obtaining two driving signals with a phase difference of 180°. In order to prevent the problem of circulating current between the two transducers, it is necessary to connect the balun transformer in series in the circuit.
[0004] However, the prior art has the following defects:
[0005] 1) A high-power generator needs to be specially designed, increasing the research and production costs;
[0006] 2) The use of transformer reverse phase can only achieve a fixed 180° phase difference, and the phase cannot be adjusted, limiting the application range;
[0007] 3) Balun transformers must be used to balance the current, increasing the complexity of the system
[0008] and cost;
[0009] 4) The two transducers are usually monitored as a whole, and it is difficult to independently protect a single transducer. When the master-slave transducer characteristics deviate greatly, the transducer with excessive amplitude is easily damaged due to the lack of independent monitoring;
[0010] 5) Special equipment needs to be customized, inventory management is complex, and maintenance costs are high. SUMMARY
[0011] In view of the above, the purpose of the present application is to solve the above technical deficiencies in the prior art method for the coordinated control of two ultrasonic generators during high-power ultrasonic welding, and to propose a method for the synchronous control of ultrasonic generator double-machine linkage welding.
[0012] The application discloses a synchronous control method for ultrasonic generator double-machine linkage welding, characterized in that two ultrasonic generators capable of independently driving transducers are respectively set as a master ultrasonic generator and a slave ultrasonic generator; the master ultrasonic generator and the slave ultrasonic generator are connected through a synchronous expansion board and a communication cable for signal transmission; the master ultrasonic generator simultaneously generates a master driving signal and a slave driving signal with controllable phase in PWM processing; the slave driving signal generated by the master ultrasonic generator is transmitted to the slave ultrasonic generator through the synchronous expansion board and the communication cable; the master ultrasonic generator drives a master transducer according to the master driving signal; after receiving the slave driving signal, the slave ultrasonic generator gives up the control of its own driving signal and drives a slave transducer according to the slave driving signal, and only retains a protection monitoring function.
[0013] The application further limits the technical scheme, and the features include:
[0014] The communication cable is a network cable, four of the eight lines of the network cable form two pairs of differential signal lines for transmitting the slave driving signal generated by the master ultrasonic generator, two of the eight lines form a pair of differential lines for RS485 communication between the master ultrasonic generator and the slave ultrasonic generator, one line is used as an independent ground line, and one line is used as a start signal and an error synchronization line.
[0015] The synchronous expansion board comprises a differential signal conversion chip, a direction control circuit and a synchronous signal processing circuit.
[0016] The differential signal conversion chip converts the PWM signal output by the master ultrasonic generator into a differential signal and transmits the differential signal to the slave ultrasonic generator through the communication cable, or converts the differential signal received by the slave ultrasonic generator into a PWM signal and provides the PWM signal to the MCU of the slave ultrasonic generator or directly drives the inverter circuit of the slave ultrasonic generator.
[0017] The direction control circuit controls the differential signal conversion chip to switch between the receiving state and the transmitting state according to the direction switching signal output by the MCU of the master ultrasonic generator.
[0018] The synchronous signal processing circuit comprises a resistor R16, a resistor R17, a capacitor C25 and a TVS tube D4, the resistor R16, the resistor R17 and the capacitor C25 are arranged between the synchronous signal line end of the communication cable interface, the MCU synchronous line end of the master ultrasonic generator and the slave ultrasonic generator, a high level and the ground to form an input protection circuit, and the TVS tube D4 is arranged between the synchronous signal line end of the communication cable interface and the ground to provide transient voltage protection.
[0019] In the start state of the slave ultrasonic generator, the slave ultrasonic generator monitors the synchronous signal, and when it is detected that the synchronous signal is pulled low, the slave ultrasonic generator executes immediate shutdown protection.
[0020] From the ultrasonic generator start state, periodically send real-time power and other measurement data to the master ultrasonic generator; when an anomaly is detected, pull down the synchronization signal for a period of time to notify the master ultrasonic generator to shut down.
[0021] The RS485 communication content includes: the master ultrasonic generator sends the working frequency information to the slave ultrasonic generator; and the slave ultrasonic generator replies to the master ultrasonic generator including but not limited to power, current, voltage, amplitude and impedance and other operating parameters.
[0022] The phase-controllable slave machine driving signal is 0°-360° phase control adjustment.
[0023] The beneficial effects of the present application are:
[0024] 1) The present application uses the existing ultrasonic generator to increase the synchronization expansion board to realize the cooperative control of two ultrasonic generators, without the need for special design of high-power generator, which significantly reduces the research and development, production and inventory costs;
[0025] 2) The driving signal of the two ultrasonic generators supports 0°-360° arbitrary phase adjustment, which is not only suitable for 180° push-pull driving, but also can be used for various applications requiring phase difference adjustment, such as ultrasonic processing, which expands the application range;
[0026] 3) The two independent ultrasonic generators each have an independent loop, avoiding the use of a balun transformer, reducing system cost and complexity;
[0027] 4) The master-slave transducer can be independently and completely monitored and protected, improving system reliability and transducer service life;
[0028] 5) The two ultrasonic generators are completely consistent in hardware, and are only distinguished by software settings, simplifying production, inventory management and maintenance;
[0029] 6) Only one network cable is needed to realize all synchronization functions, including driving signal transmission, communication and error synchronization, with simple wiring;
[0030] 7) Differential signal transmission is adopted, which has strong anti-interference ability and ensures signal transmission reliability. BRIEF DESCRIPTION OF DRAWINGS
[0031] Figure 1 It is a system framework structure diagram of the present application;
[0032] Figure 2 It is a synchronization signal circuit principle diagram of the present application;
[0033] Figure 3 It is a master-slave synchronization circuit principle diagram of the single-channel PWM signal of the present application;
[0034] Figure 4 Workflow diagram for the present invention. DETAILED DESCRIPTION
[0035] The technical solutions of the present invention are further described below in combination with the drawings and preferred specific embodiments of the present invention.
[0036] Referring to Figure 1 As shown in the, the disclosed ultrasonic generator double-machine linkage welding synchronous control method sets two ultrasonic generators capable of independently driving transducers as a master ultrasonic generator and a slave ultrasonic generator; that is, the two ultrasonic generators are completely consistent in hardware, and are only distinguished by software settings, the master ultrasonic generator can independently drive the master transducer, the slave ultrasonic generator can independently drive the slave transducer, and the slave ultrasonic generator can also abandon independent control and cooperatively drive the slave transducer according to the phase-controllable slave driving signal provided by the master ultrasonic generator, so that the master transducer and the slave transducer can simultaneously control their respective transducers and perform linkage with a settable phase difference, and power superposition is realized.
[0037] To realize the cooperative control of the master ultrasonic generator on the slave ultrasonic generator, the present invention adds a synchronous expansion board in the master ultrasonic generator and the slave ultrasonic generator respectively, and signal transmission is performed through the synchronous expansion board and a communication cable; the master ultrasonic generator simultaneously generates a master driving signal and a phase-controllable slave driving signal in PWM processing, the slave driving signal generated by the master ultrasonic generator is transmitted to the slave ultrasonic generator through the synchronous expansion board and the communication cable; the master ultrasonic generator drives the master transducer according to the master driving signal; after receiving the slave driving signal, the slave ultrasonic generator abandons the control right of its own driving signal and drives the slave transducer according to the slave driving signal, and only the protection monitoring function is retained.
[0038] The slave driving signal serves as a synchronization signal for realizing the synchronous work of the slave ultrasonic generator with the master ultrasonic generator, the communication cable used in the transmission process can be a network cable, the synchronous expansion boards in the two ultrasonic generators are respectively provided with an RJ45 network port, and the network cable is inserted at both ends of the two RJ45 network ports to realize signal transmission between the master ultrasonic generator and the slave ultrasonic generator.
[0039] Referring to Figure 2 As shown in the, among the 8 lines of the network cable:
[0040] 4 lines form two pairs of differential signal lines for transmitting the slave driving signal emitted by the master ultrasonic generator; for example, the 4th pin and the 5th pin of the RJ45 network port form a pair of differential signal lines, and the 7th pin and the 8th pin form another pair of differential signal lines;
[0041] Two wires form a differential pair for RS485 communication between the master ultrasonic generator and the slave ultrasonic generator; for example, a differential pair consisting of pins 1 and 2 of an RJ45 network port.
[0042] One wire serves as an independent ground wire, for example, pin 3 of an RJ45 network port;
[0043] One wire serves as both the start signal and the error synchronization line, such as pin 6 of an RJ45 network port.
[0044] Reference Figure 2 and Figure 3 As shown, the synchronization expansion board includes: a differential signal conversion chip U2, a direction control circuit, and a synchronization signal processing circuit;
[0045] The differential signal conversion chip U2 converts the PWM signal output by the main ultrasonic generator into a differential signal and transmits it to the slave ultrasonic generator via a communication cable; or it converts the differential signal received from the slave ultrasonic generator into a PWM signal and provides it to the MCU of the slave ultrasonic generator or directly drives the inverter circuit of the slave ultrasonic generator; the PWM signal provided to the MCU of the slave ultrasonic generator serves as a phase-controllable slave drive signal, and the slave ultrasonic generator controls the power transistor according to the PWM signal to drive the slave transducer to work;
[0046] The direction control circuit controls the differential signal conversion chip to switch between transmit and receive states based on the direction switching signal output by the MCU of the main ultrasonic generator; for example... Figure 3 When the HRTIM_SYCN_DE terminal of the differential signal converter chip U2 is high, the differential signal converter chip U2 is configured in output mode; when it is low, it is in input mode.
[0047] The synchronization signal processing circuit includes resistors R16 and R17, capacitor C25, and TVS diode D4. Resistors R16, R17, and C25 are respectively located between the synchronization signal line terminal of the communication cable interface and the MCU synchronization line terminal of the main ultrasonic generator / slave ultrasonic generator, the high level, and ground, forming an input protection circuit. TVS diode D4 is located between the synchronization signal line terminal of the communication cable interface and ground to provide transient voltage protection.
[0048] Reference Figures 2 to 4 As shown, the working process of the main ultrasonic generator of the present invention includes:
[0049] In standby mode, the control synchronization signal outputs a low level;
[0050] Upon startup, the HRTIM_SYCN_DE signal outputs a high level, putting the differential signal conversion chip U2 in the signal output state;
[0051] The PWM driving signal generated by the MCU of the master ultrasonic generator is converted into a differential signal by the differential signal conversion chip U2, and is transmitted to the slave ultrasonic generator through a network cable;
[0052] The synchronous signal output high level of the control open-drain output informs the slave ultrasonic generator to start;
[0053] The master ultrasonic generator monitors the synchronous signal, and when detecting that the synchronous signal is pulled low by the slave ultrasonic generator, executes immediate shutdown protection.
[0054] The working process of the slave ultrasonic generator includes:
[0055] After the synchronization function is started, the HRTIM_SYCN_DE signal outputs low level, so that the differential signal conversion chip U3 is in a signal input state;
[0056] The differential signal transmitted by the master ultrasonic generator is converted into a PWM signal to directly control the power tube to drive the slave transducer;
[0057] When the synchronous signal high level is detected, the measurement monitoring function is started;
[0058] Real-time power and other measurement data are periodically sent to the master ultrasonic generator;
[0059] When an abnormality is detected, the synchronous signal is pulled low, and after the synchronous signal is pulled low for 100 ms, the host computer is informed to stop.
[0060] The RS485 communication content includes that the master ultrasonic generator sends working frequency information to the slave ultrasonic generator, and the slave ultrasonic generator returns operation parameters, including power, current, voltage, amplitude and impedance, to the master ultrasonic generator; the master ultrasonic generator integrates the data of the two machines, and calculates total power and energy consumption.
[0061] The phase-controllable slave driving signal is 0°-360° phase control adjustment, which is not only suitable for 180° push-pull driving, but also can be used for various applications requiring phase difference adjustment, for example, ultrasonic processing.
[0062] Referring to Figure 2 and Figure 3 As shown, the slave ultrasonic generator receives the driving signal sent by the master ultrasonic generator, gives up the control right of the driving signal, and only retains the protection monitoring function. The HRTIM_SYCN_DE signal controls the signal input or output direction of the pins A and B of the differential signal conversion chip U2;
[0063] The PWM driving signal is connected to the HRTIM_SYCN_1_TX pin through the resistor R12;
[0064] Resistors R6 and R7 are pull-down resistors, and impedance matching resistor R2 provides appropriate impedance to ensure signal stability.
[0065] U9 is an AND gate chip, ensuring that the slave can only obtain the driving signal during the synchronization signal is high
[0066] The differential signal is output to the network cable through OUT_SYCN_A and OUT_SYCN_B.
[0067] Example 1: Master ultrasonic generator working process
[0068] When the ultrasonic generator is set to master mode:
[0069] 1) Initialization phase:
[0070] • Configure the synchronization signal GPIO as an open-drain output mode;
[0071] • Output low, indicating that the system is in standby state;
[0072] • HRTIM_SYCN_DE outputs high, configuring the differential signal conversion chip U2 to output mode.
[0073] 2) Start working phase:
[0074] • The HRTIM timer of the master MCU (such as STM32G474) generates two PWM signals;
[0075] • The first one is used to drive the master transducer;
[0076] • The second one is sent to the slave ultrasonic generator after phase adjustment (such as 180°) through the synchronization expansion board;
[0077] • The synchronization signal configured as an open-drain output mode outputs high, notifying the slave ultrasonic generator to start.
[0078] 3) Running monitoring phase:
[0079] • Continuously monitor the synchronization signal state;
[0080] • Receive the running parameters sent by the slave ultrasonic generator through RS485;
[0081] • Integrate dual-machine data and calculate total power;
[0082] • If it is detected that the synchronization signal is pulled low, immediately stop PWM output.
[0083] Example 2: Slave ultrasonic generator working process
[0084] When the ultrasonic generator is set to slave mode:
[0085] 1) Initialization phase:
[0086] • Configure synchronization signal GPIO as input mode, enable interrupt;
[0087] • HRTIM_SYNCN_DE output low, configure differential chip as input mode;
[0088] • Disable the function of PWM output from ultrasonic generator.
[0089] 2) Wait for start phase:
[0090] • Monitor synchronization signal, wait for high level trigger;
[0091] • Receive frequency information sent by the main ultrasonic generator through RS485.
[0092] 3) Running work phase:
[0093] • After detecting the high level of synchronization signal, start measurement protection function;
[0094] • Receive PWM signal sent by the main ultrasonic generator, directly drive power tube;
[0095] • Send measurement data to the main ultrasonic generator every 2ms;
[0096] • Real-time monitor transducer parameters (voltage, current, amplitude, impedance, etc.).
[0097] 4) Abnormal protection phase:
[0098] • When detecting parameter abnormality, configure GPIO as output mode;
[0099] • Output low level for 100ms, notify host to stop;
[0100] • Record abnormal information, wait for the main ultrasonic generator to query.
[0101] Example 3: Communication protocol
[0102] RS485 communication adopts master-slave protocol:
[0103] 1) Host broadcasts regularly:
[0104] • Current working frequency (2 bytes);
[0105] • Working state (1 byte);
[0106] • Command word (1 byte).
[0107] 2) Slave response:
[0108] • Device status (1 byte);
[0109] • Real-time power (2 bytes);
[0110] • Current effective value (2 bytes);
[0111] • Amplitude value (2 bytes);
[0112] • Impedance value (2 bytes);
[0113] • Error code (1 byte).
[0114] 3) Communication parameters:
[0115] • Baud rate: 115200 bps;
[0116] • Data format: 8-bit data bits, 1-bit stop bit, no check;
[0117] • Communication period: 2 ms in normal operation, 100 ms in standby.
[0118] Example 4: Phase adjustment application
[0119] The present application is not limited to 180° push-pull driving, and can realize any phase difference:
[0120] 1) Ultrasonic processing application:
[0121] • Set the phase difference to 90° to realize elliptical vibration;
[0122] 2) Phase adjustment method:
[0123] • In the main ultrasonic generator HRTIM configuration, the phase difference of two PWMs is set by modifying the comparator of the Master timer to synchronize to different sub-timers;
[0124] • The phase resolution can reach 1°;
[0125] • Supports dynamic adjustment without the need to stop.
[0126] Example 5: System configuration
[0127] System configuration is simple and flexible:
[0128] 1) Hardware configuration:
[0129] • The master ultrasonic generator and the slave ultrasonic generator use the same generator and synchronization board;
[0130] • Connect through standard network cable (CAT5e or higher), and higher specification network cable should be used in high interference situations;
[0131] • Use shielded network cable, length not more than 10 meters.
[0132] 2) Software configuration:
[0133] • Select the working mode in the ultrasonic generator setting menu:
[0134] o Master mode: send synchronization signal;
[0135] o Slave mode: receive synchronization signal;
[0136] o Off mode: work independently.
[0137] 3) Parameter setting:
[0138] • Phase difference: 0°-359° adjustable; • Protection parameters: each protection threshold value can be independently set.
[0139] The application realizes the function of using standard equipment to complete high-power ultrasonic welding by the innovative double-machine synchronization method, not only reduces the cost, but also improves the flexibility and reliability of the system. The method is especially suitable for metal welding and ultrasonic processing applications that require high-power output.
[0140] The above description is only the preferred embodiment of the application, and is not intended to limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.
Claims
1. A method for synchronous control of ultrasonic generator double-machine linkage welding, characterized in that The method sets two independently drivable transducer ultrasonic generators as a master ultrasonic generator and a slave ultrasonic generator; the master ultrasonic generator and the slave ultrasonic generator transmit signals through a synchronous expansion board and a communication cable; the master ultrasonic generator simultaneously generates a master driving signal and a phase-controllable slave driving signal in PWM processing, and the slave driving signal is transmitted to the slave ultrasonic generator through the synchronous expansion board and the communication cable; the master ultrasonic generator drives a master transducer according to the master driving signal; after receiving the slave driving signal, the slave ultrasonic generator gives up the control of its own driving signal, drives a slave transducer according to the slave driving signal, and only retains a protection monitoring function; the synchronous expansion board comprises a differential signal conversion chip, a direction control circuit and a synchronous signal processing circuit; The differential signal conversion chip converts the PWM signal output by the MCU of the master ultrasonic generator into a differential signal and transmits the differential signal to the slave ultrasonic generator through the communication cable, or converts the differential signal received by the slave ultrasonic generator into a PWM signal and provides the PWM signal to the MCU of the slave ultrasonic generator; The direction control circuit controls the differential signal conversion chip to switch between the receiving and transmitting states according to the direction switching signal output by the MCU of the master ultrasonic generator; The synchronous signal processing circuit comprises a resistor R16, a resistor R17, a capacitor C25 and a TVS tube D4, the resistor R16, the resistor R17 and the capacitor C25 are arranged in an input protection circuit between the synchronous signal line end of the communication cable interface and the MCU synchronous line number end, the high level and the ground of the master ultrasonic generator\slave ultrasonic generator; the TVS tube D4 is arranged between the synchronous signal line end of the communication cable interface and the ground, and provides transient voltage protection.
2. The dual generator synchronization control method of claim 1, wherein: The communication cable is a network cable, four of the eight lines of the network cable form two pairs of differential signal lines for transmitting the slave driving signal generated by the master ultrasonic generator, two of the eight lines form a pair of differential lines for RS485 communication between the master ultrasonic generator and the slave ultrasonic generator, one line is used as an independent ground line, and one line is used as a start signal and an error synchronization line.
3. The dual generator synchronization control method of claim 1, wherein: In the slave ultrasonic generator start state, the slave ultrasonic generator monitors the synchronization signal, and when it is detected that the synchronization signal is pulled low, immediate shutdown protection is performed.
4. The dual generator synchronization control method of claim 3, wherein: In the slave ultrasonic generator start state, the slave ultrasonic generator periodically sends real-time power measurement data to the master ultrasonic generator; when an abnormality is detected, the synchronization signal is pulled low to notify the master ultrasonic generator to shut down.
5. The dual generator synchronization control method of claim 2, wherein: The RS485 communication content comprises that the master ultrasonic generator sends working frequency information to the slave ultrasonic generator, and the slave ultrasonic generator returns power, current, voltage, amplitude and impedance operating parameters to the master ultrasonic generator.
6. The dual generator synchronization control method of claim 1, wherein: The phase-controllable slave driving signal is a 0°-360° phase control adjustment.
Citation Information
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Multi-welding-machine coordinated control device and method and welding system
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